chore: update pull_request_template.md

.github/pull_request_template.md

@@ -34,6 +34,7 @@
 -   [ ] I have commented my code, particularly in hard-to-understand areas
 -   [ ] I have made corresponding changes to the documentation
 -   [ ] My changes generate no new warnings
+-   [ ] I have run `yarn prettier` and `yarn lint` without getting any errors
 -   [ ] I have added tests that prove my fix is effective or that my feature works
 -   [ ] New and existing unit tests pass locally with my changes
 -   [ ] Any dependent changes have been merged and published in downstream modules